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AN electrical exhibition on a large scale was opened at Olympia, Kensington, on September 25 by the Lord Mayor of London. The exhibition is under the auspices of the National Electrical Manufacturers' Association (Incorporated), and is intended to demonstrate the powers and uses of electricity in domestic, manufacturing, and commercial directions. Among the special exhibitors are the General Post Office and the Marconi Company. The Institution of Electrical Engineers is taking an interest in the exhibition on the educational side; and a series of popular scientific lectures and demonstrations has been arranged upon wireless telegraphy, electric motor developments, domestic lighting, telegraphy, telephones, and other subjects.

IN NATURE of July 13 (p. 244) there appeared a letter by Mr. Rotch, director of the Blue Hill Meteorological Observatory, U.S.A., describing the Franco-American expedition for the exploration of the atmosphere in the tropics which was sailing on M. Teisserenc de Bort's steam yacht Otaria. During a two months' cruise, the scientific members of the expedition, Messrs. Maurice, of Trappes Observatory, and Clayton, of Blue Hill, executed thirty-two soundings with balloons and kites, and made observations on two tropical peaks, all between latitudes 9° and 37° N. and longitudes 16° and 31° W. A southerly or south-westerly return trade was found at a height of about two miles in the tropics and an easterly wind in the equatorial regions, confirming the generally accepted theory of atmospheric circulation. While the detailed observations are to be published in a special volume by Messrs. Teisserenc de Bort and Rotch, the general results of the investigation will, it is hoped, be embodied in an article which will appear in the columns of NATURE.

THE first congress of the International Surgical Society was held from September 18-22 at the Palais des Académies in Brussels under the patronage of King Leopold. A correspondent of the Times says that more than two hundred delegates attended, representing the following countries :-Great Britain, France, Germany, Austria-Hungary, the United States, Belgium, Holland, Switzerland, Japan, Russia, Spain, Portugal, Sweden, Norway, Italy, Denmark, Greece, Finland, Rumania, Servia, and Egypt. The subjects discussed were of a purely technical order, and papers were read on the latest development of surgical science. An interesting feature of the congress was an exhibition of the latest surgical appliances. The delegates received a cordial welcome from the Government and municipal authorities and from their local colleagues. The last meeting of the congress was held on Saturday, September 23. During the session a congratu latory telegram was sent in the name of the society to Lord Lister on the great progress of surgery directly resulting from his antiseptic discoveries. It was resolved that the second congress should also be held in Brussels in 1908. Prof. V. Czerny, professor of surgery in the University of Heidelberg, was appointed president, and the various national committees were also nominated.

THE l'ictorian Naturalist announces the death of Mr. H. T. Tisdall, formerly president of the Field Naturalists' Club of Victoria, and an active botanical teacher and investigator. In September, 1883, he contributed his first paper to the club, the title being "A Botanical Excursion in North Gippsland." Having to a great extent exhausted the phanerogams of the district, he was induced by Baron von Mueller to turn his attention to the cryptogams, with

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the result that he became an authority on fungi, and at the meeting of the club in February, 1885, contributed a paper entitled The Fungi of Mt. Baw Baw," in which he described some twelve species of the genus Agaricus. In November of the same year he contributed a further paper on the fungi of North Gippsland, in which he made some important remarks regarding the fungus then known as Mylitta australis, "Native Bread." During the interval of nearly twenty-one years between his first and last papers, he contributed numerous papers to the meetings of the club, all relating more or less to botany, either as bearing on a particular branch or descriptive of trips ar excursions in search of specimens. In addition to his knowledge of Victorian phanerogamic and cryptogamic plants, Mr. Tisdall was, at the time of his death, an authority on marine algæ. He contributed an article on the flora of Walhalla to the mining department's report on that goldfield (1902), as also some useful papers to the meetings of the Australasian Association for the Advancement of Science, which included a list of the marine alga of Victoria.

IN l'Anthropologie (xvi., No. 3) M. Boule gives a more detailed account of the machine-made coliths referred to in his paper in the Comptes rendus, translated in NATURE of August 31 (p. 438). From the descriptions and illus trations, it appears that among the specimens collected

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no longer be cited in proof of human antiquity greater than can be assumed on other grounds. Eolithic forms may be due to human agency, but independent proof of the contemporary existence of man in the area in question is henceforth indispensable.

THE latest issue (vol. viii., part i.) of the Transactions of the Norfolk and Norwich Naturalists' Society contains a number of interesting papers, mostly dealing with the natural history and antiquities of the county. The papers on local biology include one on the water-beetles of the ** Broads " by Mr. F. B. Browne, another on the hydrachnids of the same district by Mr. C. D. Soar, notes on the Yarmouth herring-fishery of last year by Mr. T. J. Wigg, lists of Norfolk lichens and liverworts by the Rev. E. N. Bloomfield, and an account of the rotifers of the county by the Rev. R. Freeman.

WE have received from Dr. E. M. Goeldi, director of the museum at Parà, a budget of separate copies of papers by himself, published, with the exception of one, in the Comptes rendus of the sixth zoological congress held at Berne last summer. The one exception is from the Ibis for April, and deals with the habits of a Brazilian tyrantbird (Myiopatis semifusca); this species, in place of being insectivorous, feeding on the fruits of a parasitic plant and disseminating the seeds, thus causing harm to arboriculture. The other papers relate to rare animals from Amazonia, the yellow-fever mosquito (Stegomyia fasciata), and the habits of ants of the genus Atta.

WE have received two new parts of the reports of the scientific results of the voyage of the Belgica, 1897-9, issued at Antwerp, in one of which Prof. H. Leboucq discusses the development of the flippers of Antarctic seals from the point of view of the evolution of the pinnipeds in general, while in the second Mesdames Bommer and Rousseau describe the funguses collected during the cruise, all of which, with the exception of a single Antarctic specimen, were obtained from Tierra del Fuego. Judging from the collection, the fungus-fauna of the latter area appears to be a rich one of which but little is at present known. Prof. Leboucq's article is the first of a series on the organogenie of the seals. In the case of both memoirs we may direct attention to the difficulty they present to recorders of biological literature, or, for that matter, to anyone who desires to quote from them. They are respectively headed "Zoologie and Botanique," but, despite the fact that they are not the first issues of those two series, each is separately paged, and neither bears any volume number. Consequently the whole title has to be quoted for reference purposes.

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where by aid of constant syringing they were induced to bloom in a hothouse, when it was found that the petals are so arranged as to form a kind of penthouse for the protection of the central organs from the constant showerbath existing in the "rain-forest."

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AN important issue of the Palaeontologia Indica (Mem. Geol. Survey of India) is devoted to the description of some recently discovered vegetable and vertebrate remains from the permo-Carboniferous strata of the Vihi Valley, fifteen miles to the south-east of the city of Srinagar, Kashmir. The remains in question were discovered by Noetling in beds apparently underlying the marine Kuling series (Permian) of the Kashmir Valley; and as they include a member of the "glossopteris flora of the Lower Gondwana system of peninsular India, their discovery serves to confirm the reference of these deposits to the Upper Palæozoic. The plant remains, which are described by Mr. A. C. Seward, include only one generically determinable type, namely, Gangamopteris, from the base of the lower Gondwanas of the peninsula. The vertebrates, for the identification of which Dr. A. S. Woodward is responsible, include a couple of species of the palæoniscid ganoid genus Amblypterus, nearly allied to Lower Permian from Rhenish Prussia, and fragments of a labyrinthodont amphibian apparently referable to Archegosaurus, a genus known elsewhere only from the last mentioned and equivalent formations. No reference is made to the labyrinthodont from the Lower Gondwanas of the peninsula described as Gondwanosaurus, but originally referred to Archegosaurus.

IN the third part of his contribution to the study of the mischievous insects commonly known as leaf-hoppers and their enemies, published at Honolulu as part iii. of the first Bulletin of the Experiment Station of the Hawaiian Sugar-Planters' Association, Mr. R. C. L. Perkins furnishes some very interesting information with regard to the lifehistory of the parasitic Stylopida (Strepsiptera). It appears that although the majority of those degraded beetles infest bees and wasps, a certain number of species are parasitic on leaf-hoppers and other Homoptera, and it is the latter that form the subject of the communication before us. Although death usually follows some time after being stylopised," many leaf-hoppers are able to procreate their kind after being badly affected by the parasites, especially if by females. The male stylopids, on account of the larger size of the puparia, are, however, much more speedily fatal to the leaf-hoppers, the hole left in the bodies of the latter by the escaping insect being relatively large. Moreover, a fungus immediately makes its appearance, with fatal effect, in the tube; and in artificially infecting leaf

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importance that the fungus should also be introduced.

ACCORDING to the report for the year ending in May hoppers with stylopids it is considered of the highest last, the Rhodesia Scientific Association, now in the seventh year of its existence, continues to make satisfactory progress, both as regards the length of its roll of members and in the work accomplished. With the report we have received a copy of the fourth volume (1903-4) of the association's Proceedings, which contains a number of papers dealing with the biology and antiquities of the country, together with one on its soils. The latter do not appear to be so promising as might have been hoped, most of them possessing only a moderate degree of fertility, and none exhibiting that redundant growing capacity we are accustomed to associate with virgin lands. Perhaps the most generally interesting paper is one on a new gladiolus which grows in the spray of the Victoria Falls, and has therefore been called the Maid of the Mist." Four bulbs were sent to England,

THE report on economic zoology contributed by Prof. Theobald, of Wye Agricultural College, to the college journal for the year 1904-5 deals chiefly with the insect pests of field and garden crops, and on this important subject gives a great deal of useful information. During the year Prof. Theobald dealt with about 1200 communications, and his report contains descriptions of the most troublesome pests brought to his notice. Among the pests of fruit trees, the apple aphides Aphis pomi, A. sorbi, and A. fitchii were much the most destructive. Prof. Theobald points out that these forms have been wrongly described as a single species, A. mali, by previous English writers. The aphides do great damage to young shoots, leaves, and blossoms, but it is apparently hopeless to attempt to get rid of them by spraying in the usual

way in spring. The only practical remedy, especially where the first two species are concerned, is to spray in autumn, and a heavy paraffin emulsion is recommended, as injury to the leaves is not a serious matter at this season. The work is troublesome but effectual. In many cases it may be possible to collect and burn affected leaves in autumn, and this is recommended. Prunings should also be burnt before March. In the same report Prof. Theobald mentions a case in which honey-comb was destroyed by the maggots of the window fly (Rhyphus fenestralis). The window fly is a very common insect, but has never before been reported as an enemy of the bee, and the case is mentioned as showing how a harmless insect may suddenly change its habits and become a pest.

Two recent botanical parts, Nos. 9 and 11, of vol. xii. of the Proceedings of the American Academy of Arts and Sciences deal with systematic work. In the one number Mr. B. L. Robertson collates some American Eupatorieæ, and Mr. J. M. Greenman presents a list of new flowering plants from Mexico and the south-western United States. In addition to the new species, Mr. Greenman proposes two new genera, Lozanella, near to Trema, of the order Ulmacea, and Mimophytum, a borraginaceous genus allied to Omphalodes and Cynoglossum. The other part contains the sixth and last of the preliminary diagnoses by Prof. R. Thaxter on new species of Laboulbeniaceæ, a specialised group of minute ascomycetous fungi which live parasitically on insects.

SEVERAL points of interest are noted in a phytogeographical sketch by Dr. L. Cockayne of the vegetation of the two Open Bay islands, which lie close to the shore of South Westland, a county in the southern island of New Zealand. Characteristic liane formations occur on both islands; on the larger northerly island the dominant liane is a screw-pine, Freycinetia Banksii, and in some parts, Muehlenbeckia adpressa, of the order Polyonaceæ, is associated with it or takes its place; on the smaller island the Freycinetia is absent, and the Muehlenbeckia forms pure scrub or grows with a large-leaved variety of Veronica elliptica. The account appears in the Transactions of the New Zealand Institute (vol. xxxvii.), as also a list of newly-recorded habitats for New Zealand plants by the same writer. The identification of a Carex from Chatham Island, as a variety otherwise only recorded from Patagonia, adds another to the list of plants which connects the floras of New Zealand and South America.

AT the age of four score years, Dr. v. Neumayer has the satisfaction of issuing the third edition of his Anleitung zu wissenschaftlichen Beobachtungen auf Reisen." It is appearing in parts (Jaennecke, Hanover) at a price of 36 marks, and will comprise two volumes, the first dealing with geography and inanimate nature, the second with plants, animals, and man. More than thirty experts are collaborating under Dr. v. Neumayer's editorship, so that each subject will be treated by an expert. The first two parts have already appeared, and contain articles on geographical observations, directions for somatological observations, an anthropological questionnaire, which seems to be identical with that issued by the Berlin Museum for Africa, and, finally, the commencement of an excellent article by Dr. v. Luschan on field work in archæology. No provision seems to be made for an article on a traveller's outfit or general hints; but it would not materially increase the size of the book to do so, and probably its general usefulness would be much increased by the addition. The last edition appeared in 1888, and

in many branches of knowledge the advance since that date has been immense. It is therefore a matter for congratulation that Dr. v. Neumayer has been able to supervise the re-issue and gather around him so many able coadjutors.

A COMMISSION has been appointed by the LieutenantGovernor of the Transvaal to consider the question of the safety of persons travelling in shafts. It will inquire into the structure, material, preservation, and examination of winding ropes and the adaptability of safety catches.

MESSRS. PERCIVAL, MARSHALL AND CO. have published a useful little guide to standard screw threads and twist drills by Mr. George Gentry. Tables are given of the Whitworth standard thread, the British Association standard, bicycle screw threads, the V standard thread, the United States standard thread, the international metric standard thread, watch and clock screws, and twist drills. The guide, which is published at nd. net, is specially designed to meet the needs of the model engineer, and shows in a striking manner the necessity for the general adoption of standard threads as advocated in an article recently published in NATURE (August 31).

THE current

issue of the Bulletin de la Société d'Encouragement contains an important memoir by a Swedish engineer, Mr. Hjalmar Braune, on the influence of nitrogen on iron and steel. That metalloid exerts an influence more harmful even than that of phosphorus, and appears to be the chief cause of the fragility of mild steel. Its presence in iron is not due to the direct combination of the metal with the nitrogen of the air; the intervention of basic slag is necessary. Metal made by the Thomas and Gilchrist process contains more nitrogen than steel made by the acid process, and this explains the inferiority generally ascribed to the former material.

THE annual report on the mineral resources of the United States for 1903 has been issued under the able editorship of Dr. David T. Day. It forms a bulky volume of 1204 pages, and contains, in addition to statistics of production, a large amount of descriptive and technical matter. In 1903, for the fourth time, the total value of the United States mineral production exceeded 200,000,000l., iron and coal being the most important of the mineral products. The United States in 1903 were the greatest producers of iron, coal, copper, lead, petroleum, and salt in the world. Tin, it is interesting to note, has been found in commercial quantities in South Carolina, and the mines were actively worked in 1903. The manufacture of arsenious acid, a new industry in the United States, is carried on at Everett, Washington. The production of gypsum continues to show a remarkable increase, owing, doubtless, to the use of plaster of Paris in large modern buildings. There was, too, a notable increase in the production of the ores of nickel, cobalt, chromium, tungsten, molybdenum, vanadium, titanium, and uranium owing to their use for steel-hardening purposes. A great advance in the lapidary industry is also reported. The fact that larger establishments have been formed, which are able to purchase the rough diamonds in greater quantities, has placed the American diamond-cutters in a position equal to that held by those of Amsterdam, Antwerp, and Paris The cutting of American gems has also assumed lar proportions, notably in the cases of the beryls and amethysts of North Carolina and Connecticut, and of the turquoises, sapphires, tourmalines, chrysoprases, and garnets of other States.

THE Department of Agriculture and Technical Instruction for Ireland is publishing a series of Bulletins upon experimental science, and No. 4 of this series, relating to "Voltaic Electricity," has just been issued. It has been prepared by Mr. James Comerton, and is a useful little pamphlet of thirty pages with numerous illustrations. The author states in the introduction that the experiments described are merely intended to introduce the student to the more systematic study of electrical measurements. When the student has worked through the forty-three experiments described in this pamphlet, it is hoped that he will have a fair general working knowledge of voltaic electricity-its generation, measurements, and the purposes to which it can be applied. Primary cells, resistances, galvanometers, and voltameters are illustrated, and their use is described in these pages. The handbook should prove a useful addition to the literature of elementary electrical measurements.

THE principal centres of the calcium carbide industry in France are in the Alps and Pyrenees. At present, according to a writer in the Journal of the Society of Arts, there are eleven manufactories capable of producing 40,000 tons of calcium carbide annually. The total output sold during 1904 may be estimated at 18,000 tons. The average yield of gas per unit of weight of carbide is about 40 gallons per pound. The cost price per ton of calcium carbide in Europe was estimated by Prof. Lefevre, of the École des Sciences, Nantes, in 1897, at from 81. to 10l. M. Pictet, however, in the same year, thought that the product might be made at the cost of a little more than 31., by the use of a new furnace. Theoretically, said Prof. Lefevre, one pound of calcium carbide ought to produce, by its action upon water, about seven ounces of acetylene. It has been stated by one of the most important of the French firms, speaking of the production of 1904, that this was disposed of at 81. per ton, the standard accepted and declared being about 40 gallons of gas per pound. The product at the factory realises 81. per ton, and the rate for the retail dealer is 14. These figures demonstrate the advances made in manufacturing since the publication of Prof. Lefevre's treatise in 1897.

PROF. D'ARSONVAL describes in the Bulletin of the French Physical Society a new and simple form of apparatus manufactured by the Société Française de l'Acétylène dissous, which serves for the generation and automatic compression of oxygen. The gas is generated by the combustion within the compression cylinder of a combustible substance mixed with potassium chlorate, the heat produced being sufficient to liberate the whole of the oxygen from the chlorate. The largest form of apparatus, the industrial type, gives a production of about to cubic feet of oxygen per hour. A new form of oxyacetylene burner is also described by means of which a very intense light is produced by allowing the jet to impinge upon a suitable mixture of the rare earths; lime and magnesia are useless for the purpose, as they are rapidly fused and channelled by the intense heat of the oxyacetylene flame.

DURING the past few years doubts have been expressed by several investigators, notably by Fitzgerald, Kahlenberg, Quincke, and Traube, of the correctness of Van 't Hoff's hypothesis that the osmotic pressure of solutions is purely a kinetic phenomenon due to the impact of the molecules of the solute against a membrane impermeable to them. This hypothesis has been so fertile of results and is so intimately associated with the progress of modern chemistry that any arguments of a subversive tendency

have, generally speaking, received little attention. In a recent number of the Atti dei Lincei (vol. xiv., ii., p. 5) Prof. A. Battelli and A. Stefanini have brought forward, however, a number of facts which, if subsequently verified, are likely to prove insuperable objections to its validity. A necessary consequence of Van 't Hoff's hypothesis is that isosmotic solutions should, under similar conditions, be equimolecular; but it is stated that several cases have been observed in which solutions possessing very different molecular concentrations are in osmotic equilibrium. The characteristic of these solutions is that they have equal surface tensions, and it is contended that osmotic pressure is essentially a capillary phenomenon. Osmosis would then be a tendency to equalise the surface tensions of the liquids on the two sides of the membrane. The further developments of the authors' experiments will be watched with interest.

AN interesting lecture device for illustrating the superposition of simple harmonic motions of different periods has been submitted to us by Mr. W. C. Baker, of the School of Mining, Queen's University, Kingston, Ontario. A horizontal bar (about 4 cm. deep and 15 cm, long) carries a pointer about 50 cm. long rigidly attached to it. This system, which must be as light as possible, is suspended by two hinges which permit it to oscillate freely about a horizontal axis. To the underside of the bar are attached two pendulums (100 cm. and 75 cm. long) the bobs of which are of equal mass, say 250 grams each. If the pendulums be displaced together through an arc of, say, 15° and then released, the pointer will be set vibrating through an are which will vary from a maximum when the pendulums are in phase with one another to very approximately zero when they are in opposition, thus illustrating the formation of beats. There is, of course, no cbvious relation between the amplitude of the mction of the pointer and that of the pendulums; the escillations of the latter give rise to periodic forces upon the horizontal bar, and the pointer indicates the resulting We may point out that a somewhat analogous device was shown by Lord Rayleigh during a recent course of lectures at the Royal Institution.

motion.

Le Radium for August contains various articles and reviews on all the branches of radio-activity, together with a summary of current researches in this subject.

THE Revue Scientifique (September 9) contains an interesting summary on trypanosomes and trypanosomiasis by Dr. Brumpt. In addition to the ordinary pathogenic forms, the trypanosomes of birds, reptiles, and fishes receive notice.

ACCORDING to La Nature (September 16), the ravages of the phylloxera in northern Spain are very serious, many of the older vineyards being almost destroyed; and it is becoming a question whether it will not be necessary to substitute cereals and fruit for the vine in the affected districts.

THE Bulletin of the Johns Hopkins Hospital for September (xvi., No. 174) contains an interesting historical article on Cotton Mather's rules of health by Prof. William Thayer, together with papers of medical interest. Cotion Mather was a divine who was born in Boston in 1663, a learned man with a remarkable literary style, and his rules are often very quaint.

IN the August number of the Journal of the Royal Microscopical Society, Mr. Conrady writes on the application of the undulatory theory to optical problems, and

notes are contributed by Mr. Nelson on the presence of a flagellum at each end of the tubercle bacillus, by Lord Rayleigh on an optical paradox, and by Dr. Lazarus Barlow on a new form of hot stage. The usual summary of current researches concludes this excellent quarterly.

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MESSRS. CHARLES GRIFFIN AND CO., LTD., have published a sixth edition of Mr. Andrew Jamieson's Elementary Manual of Magnetism and Electricity." Several additions have been made in this new edition.

A KEY to the exercises in the second part of Mr. Pendlebury's "New School Arithmetic has been prepared by the author and published by Messrs. George Bell and Sons. The price of the "Key" is 8s. 6d. net.

MESSRS. SMITH, ELDER AND Co. have published a sixth edition of Marshall and Hurst's "Junior Course of Practical Zoology." The new edition has been revised throughout by Dr. F. W. Gamble, who has also added short accounts of Monocystis, Coccidium, and Obelia.

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THE following popular science lectures will be given at the Royal Victoria Hall, Waterloo Bridge Road, S.E., during next month :-October 3, A Journey of Surprises: through Yunnan to Tonquin," Mrs. Archibald Little; October 10, Smokeless Explosives," Mr. J. S. S. Brame; October 17, "The Plants of Other Days: what their Fruits and Seeds were Like," Mr. H. E. H. Smedley; October 24, 66 My Cruise Around Spain and Portugal," Mr. F. W. Gill.

MESSRS. PHILIP HARRIS AND CO., LTD., Birmingham, have just issued the third edition of their valuable catalogue of scientific instruments required in all departments of instruction or research in physics. The volume contains five hundred pages and is lavishly illustrated, a large number of the pictures representing new instruments or new methods of illustrating the principles of physical science. Many manuals and text-books of physics used in schools have been consulted, and novel forms of apparatus described in them are now made by Messrs. Harris, and appear in the present catalogue. The volume is well bound, and should be very useful for reference by teachers of physics in schools and colleges. No doubt it will find a permanent place on the bookshelves of many laboratories and lecture-rooms.

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existence of the Nova whilst examining the Draper memorial photographs on August 31. A photograph of the spectrum, taken on August 18, shows the hydrogen lines H8, Hy, and HB bright and broad, also faint traces of the bright bands at A 4472 and λ 4646. On that date the magnitude of the Nova was about 6.5, on August 21 it was 7.5, whilst on August 26 it had fallen to 10.0. No trace of the Nova is visible on a plate taken on August 10, although stars of magnitude 9.5 are shown thereon. A plate taken with the Bruce telescope at Arequipa on August 15, with an exposure of four hours, contains images of sixteenth-magnitude stars, but not of any object which can be recognised as the Nova.

A chart of the region, published by Prof. Wolf, shows the position of the Nova in regard to the star B.D. -4.4663, and further shows that the Nova occupies a position between two spaces which are void of stars down to the fifteenth magnitude.

EPHEMERIS OF THE VARIABLE ASTEROID (167) URDA.-In No. 4047 of the Astronomische Nachrichten Herr A. Berberich publishes an ephemeris for the asteroid Urda, which Dr. Palisa recently showed to be variable.

The following is an extract from this ephemeris, which was calculated from the elements published in the "* Jahrbuch" and for 12h. M.T. Berlin:

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THE ULTRA-VIOLET CHROMOSPHERIC SPECTRUM.-At the total eclipse of 1900 M. H. Deslandres devoted his attention to two special researches, of which the first was to obtain the ultra-violet spectrum of the "reversing layer," and the second to obtain a great number of plates showing the bright lines, in order to detect the changes which might take place in the chromosphere in the interval between the second and third contacts.

In the first research he was successful, and obtained a duplicate series of plates showing the bright spectrum between A 3000 and X 5000. The first series was obtained with a prismatic camera of I metre focal length, the second with a camera of half this focal length. The prisms employed were of 60° angle, and were made of Iceland spar, whilst the objectives were made up of an achromatic combination of quartz and fluorspar.

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The general results obtained from the reduction of one of the larger negatives, which was exposed for two seconds at second contact, are given in No. 9 (August 28) of the Comptes rendus, and deal only with the 157 lines photographed between A 3400 and A 3066. The chief characteristic of the spectrum in this region, as in the less refrangible region already known, is the predominance c 'enhanced titanium lines. In fact, M. Deslandres states that, considered as a whole, the spectrum is that of the titanium spark. Vanadium and chromium are represented by lines of less intensity, whilst the iron lines are extremely weak, the enhanced lines being considered in each case. The coronal radiations are represented on two other negatives by well defined lines at AA 3329.6, 3388-0, and 3447-7, the last having the greatest intensity. The same negatives, which were exposed for fifteen and thirty seconds respectively, show several prominences, and here again, the spectrum of titanium predominates.

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The chronophotographe, an instrument for photographing from six to ten spectra per second at the two contacts, was less successful, the vibration produced he its manipulation spoiling the definition. M. Deslandres gives the details of the instrument, and points out its probable efficiency if suitably mounted.

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